Collecting a concentrated cellular pellet is generally performed by placing solid tubes containing a solution of cells diluted with saline through centrifugation. After centrifugation of the tubes, a decantation process is performed to separate the cells from the supernatant. The purpose of this process is to obtain desired cells from the original solution. However, using solid tubes creates a problem because the process of placing the cells in the solid tubes makes the process an open system, as opposed to a closed system, which potentially affects the sterility of the process.